In France, if you say “je vais aux toilettes,” nobody understands that you are going to the bathroom. They understand that you are going to a small independent room containing the toilet — and only the toilet — separate from the bathroom where the shower, basin and, space permitting, the bathtub reside. They are two distinct rooms, with two distinct doors and, often enough, on opposite sides of the hallway. For a French person, the idea that someone might shower two metres from a toilet is not merely unaesthetic: it is unhygienic.

In Spain we do not share that tradition. Our bathrooms have historically been single spaces where all elements coexist, from the basin to the bathtub, passing through the toilet and the bidet. But something is changing. In the premium bathroom projects we design at Azulia — particularly in large apartments in the Valencian ensanche or in new penthouses in Campanar and Patacona — more and more clients are asking about toilet separation. Not because they have suddenly become Francophiles, but because the underlying reasons are so logical that, once you hear them, they prove difficult to ignore.

The underlying reasons: why separation makes sense

Hygiene: the aerosol problem

Let us discuss something that is not pleasant but is important. Every time a toilet is flushed without closing the lid, it generates an aerosol plume — micro-droplets of contaminated water — that can reach up to 1.5 metres in height and disperse within a 2-metre radius. A study published in the journal Physics of Fluids (University of Colorado, 2022) demonstrated through laser visualisation that these particles remain suspended for minutes and settle on every surrounding surface: toothbrushes, towels, cosmetics, basin countertop.

In a conventional bathroom, the toilet sits less than a metre from the basin area. In many Valencian bathrooms from the 1970s and 80s — those narrow rectangular layouts we all know — the toilet is literally beside the basin, separated by nothing more than a few centimetres of air.

Separating the toilet into an enclosed space with its own door eliminates this problem entirely. The aerosol remains in the toilet room, far from toothbrushes and towels. It is, from a hygiene standpoint, the most effective solution that exists. Closing the lid before flushing helps, but does not completely eliminate the dispersal.

Privacy: real-life cohabitation

Two people sharing a bathroom and getting ready in the morning simultaneously know the problem: one in the shower, the other on the toilet. Privacy is conspicuously absent. With the toilet separate, both can use their respective spaces simultaneously without discomfort. In couples, in families with teenagers, in any home where the bathroom is shared, this separation improves daily life in a way that is not appreciated until it is experienced.

And then there are guests. If you host a dinner and a guest needs to use the bathroom, would you rather they enter your full bathroom — with your products, your dressing gown hanging up, your privacy on display — or access a small independent WC? The answer seems obvious.

Design: the toilet is the ugly duckling

Let us be frank: however beautifully manufacturers design their pieces, the toilet remains the least aesthetic element in the bathroom. Its function is what it is, its form is dictated by ergonomics and its presence always feels somewhat awkward in a space that aspires to be beautiful. Separating it allows the main bathroom to become a space dedicated exclusively to wellbeing: shower, bathtub, basin, mirror. Without the presence of the toilet, the bathroom breathes differently. It becomes a space that is a pleasure to show, not one that requires justification.

In our quiet luxury designs, toilet separation is a device that enables the main bathroom to reach a level of refinement difficult to achieve with all elements in the same space.

How much space you need: the minimum dimensions

The viability of separating the toilet depends, inevitably, on the available area. These are the minimums we work with in our projects:

For the toilet room

  • Minimum width: 80 cm (clear interior). At 80 cm the toilet sits centred with just enough space on either side for the knees. It is tight but functional.
  • Minimum depth: 120 cm (clear interior). This allows 70 cm from the rear wall (where the toilet goes) to the user’s knees, plus 50 cm of clear space to open the door and move.
  • Ideal: 90 x 140 cm. At these dimensions there is genuine comfort, space for a small handwash basin and the possibility of including a shelf or accessories.

The door is a critical factor. An inward-opening hinged door needs those 120 cm of minimum depth. A sliding door or outward-opening door allows the depth to be reduced to 100–110 cm. In our projects in Valencia, where we sometimes work with inherited layouts that are not exactly generous, the pocket sliding door (which disappears inside the partition) is the solution we use most.

So the main bathroom does not suffer

Separating the toilet “steals” surface area from the main bathroom. For the operation to be worthwhile, the original bathroom should measure at least 8 m² in total before the separation. Below that figure, the risk is that both spaces feel too small and the gain in privacy does not compensate for the loss of spaciousness.

At 10–12 m² or above, the separation is almost always a net improvement. At 8–10 m², it depends on the floor plan geometry. Below 8 m², except in very favourable layouts, it is better to invest the area in a single well-designed bathroom.

Three ways to separate

Full separation: the French solution

An independent room with floor-to-ceiling walls and its own door. It is the most effective separation in terms of hygiene, privacy and acoustics. It is what we recommend when space permits and what most closely approaches the original French model.

Construction requires building a new partition (or relocating an existing one), routing plumbing to the toilet’s new position and providing independent ventilation (its own extractor or connection to the building’s ventilation shaft). The cost of the construction work ranges from 1,500 to 3,000 euros, depending on complexity.

Partial separation: the half-wall

A wall 120–150 cm in height that visually conceals the toilet without fully enclosing the space. It maintains the sense of spaciousness of a single bathroom while providing basic visual privacy. It does not resolve the aerosol or acoustic issues, but it does address the aesthetic one: the toilet disappears from the field of vision when you are in the shower or basin area.

It is the solution that works best in bathrooms of 7–9 m² where full separation would compromise the space too much. The half-wall can be topped with a countertop that serves as a shelf, creating function as well as form.

Glass separation

A fixed glass panel (clear, frosted or fluted) that separates the toilet zone from the rest of the bathroom. It maintains visual continuity and the sense of spaciousness whilst providing physical separation and, with frosted or fluted glass, sufficient visual privacy.

Fluted glass is enjoying a spectacular moment in 2026–2027 interior design: its texture filters vision without blocking light, creating an elegant effect reminiscent of the glazed doors of art deco buildings. As we explore in our statement wallpaper designs, materials with inherent personality can define the character of a space with a single decision.

Designing the small room: grand in intention

The fact that the toilet space is small does not mean it should be anodyne. In fact, the smallest WC rooms are the ones that most lend themselves to bold design gestures, precisely because the limited surface area allows expensive or eye-catching materials to be used without the budget spiralling.

Designer wallpaper

A room of 1 m² requires less than 3 linear metres of wallpaper. At 60–80 euros per roll of quality paper, we are talking about 120–200 euros of material to cover the walls with a design that in a living room would cost five times as much. It is the perfect place for that exuberant tropical paper, that daring geometric print or that artistic design you love but would never dare use in a large room.

Compact handwash basin

A small handwash basin (30–40 cm wide) inside the toilet room is a detail of civilisation that makes a difference. It allows hands to be washed without needing to go out to the main bathroom, which makes sense both hygienically (you do not carry soiled hands to the bathroom door handle) and practically (if someone is using the main bathroom, you do not need to disturb them).

Roca offers compact handwash basins specifically designed for WC rooms, with widths from 25 cm. Grohe has short-spout taps designed for these basins. The complete set (basin + tap + installation) ranges from 400 to 800 euros.

Mirror and light

A small mirror above the basin and a well-resolved light point (a designer wall sconce, a concealed LED strip) transform a functional cubicle into a space with intention. The mirror visually expands the room and the light dignifies it. No great investment is needed: 100–200 euros cover an attractive mirror and a sconce with personality.

Ventilation

An enclosed toilet room needs ventilation, without question. If it has access to a building ventilation duct, a silent extractor with a timer (activated by the light and running for 5 minutes after switching off) is the standard solution. If no duct is available, extractors with activated carbon filters can operate in recirculation mode, though they are less effective.

Ventilation is no minor detail: a poorly ventilated toilet room accumulates odours and moisture that ruin the experience. It is the kind of thing that, as they say around here, has no easy fix once the work is done.

When it is not worth it

There are situations in which, in all honesty, separating the toilet does not pay off:

  • Bathrooms under 8 m²: the division creates two uncomfortable spaces instead of one functional one. Better to invest the area in a single, well-laid-out bathroom.
  • The only bathroom in the home: if the dwelling has a single bathroom used by all family members for everything (showering, grooming, makeup, etc.), the separation can complicate more than it facilitates. It is in the second bathroom or guest WC where separation makes most sense.
  • Very limited budget: the partition, plumbing and finishes for a new toilet room do not come in below 2,000–3,000 euros. If that budget compromises the quality of other bathroom elements, it is better to prioritise. A well-resolved complete bathroom surpasses a divided bathroom with mediocre materials.

From our Valencia studio, we evaluate each case according to the actual geometry of the space, the client’s needs and the available budget. Sometimes the best recommendation is not to separate, and that too is part of our work.

With the Azulia calculator you can explore how toilet separation influences the overall renovation budget and decide whether it is worthwhile in your specific case.

Frequently asked questions

Does separating the toilet require a building permit? If it involves a non-load-bearing interior partition, a prior communication to the local authority (minor works) usually suffices. It does not typically require an architect’s project. However, if the work involves modifying waste stacks, rerouting plumbing or affecting communal elements, a major works licence may be needed. As always, we recommend consulting a technician before starting. In Valencia, the prior communication process is handled by the Urban Planning Department and takes between 1 and 3 weeks.

Can the toilet be separated without building work? Do prefabricated panels or modules exist? Prefabricated “WC cabin” modules that are dry-assembled do exist, but their aesthetic result is far inferior to bespoke construction. For a design-led bathroom, building work is unavoidable if the result is to be of a suitable standard. Fixed glass panels are the “lightest” option in construction terms, as they require only fixing profiles to the floor and ceiling, without partition walls.

Is it better to separate the toilet or install a smart toilet with odour extraction? They are not mutually exclusive, but if one must choose, the separation resolves more issues (hygiene, privacy, aesthetics) than the integrated odour extractor (which only partially addresses the odour issue). In an ideal scenario, as we detail in our high-end bathroom design process, we combine both solutions: a smart toilet within a separate space.

What about acoustics? Can everything be heard through the wall? It depends on the partition. A 7 cm brick partition with plaster offers reasonable acoustic insulation. A plasterboard partition with double boarding and mineral wool insulates better than brick. For optimal insulation, an acoustic perimeter strip at the base of the partition can be added to prevent sound transmission through the floor. There is no need to soundproof as one would a recording studio, but a minimum of attention to acoustic detail makes a difference.

Separating the toilet from the bathroom is one of those decisions that, viewed from the outside, seems like an unnecessary luxury. But viewed from within — from daily cohabitation, from hygiene, from the pleasure of having a main bathroom free of function and full of intention — it proves one of the most sensible improvements one can make in a home. If your space allows it, it merits serious consideration. And if you need help assessing whether it is viable in your case, we are just a conversation away.